<!doctype html>
<title>::part():dir() invalidation</title>
<link rel="author" title="Keith Cirkel" href="mailto:wpt@keithcirkel.co.uk" />
<link rel="help" href="https://drafts.csswg.org/css-shadow-parts/#part" />
<link rel="help" href="https://github.com/whatwg/html/pull/8467" />
<style>
  my-element::part(inner) {
    background-color: #ff0000;
  }
  my-element::part(inner):dir(ltr) {
    background-color: #00ff00;
  }
  my-element::part(inner):dir(rtl) {
    background-color: #0000ff;
  }
</style>
<body>
  <my-element id="subject"></my-element>
  <script src="../../../resources/testharness.js"></script>
  <script src="../../../resources/testharnessreport.js"></script>
  <script>
    const RED = "rgb(255, 0, 0)";
    const GREEN = "rgb(0, 255, 0)";
    const BLUE = "rgb(0, 0, 255)";
    customElements.define(
      "my-element",
      class MyElement extends HTMLElement {
        connectedCallback() {
          this.attachShadow({
            mode: "open",
          }).innerHTML = `<div part="inner">Test</div>`;
          this.elementInternals = this.attachInternals();
        }

        get inner() {
          return this.shadowRoot.querySelector("[part=inner]");
        }
      },
    );

    test((t) => {
      t.add_cleanup(() => {
        subject.inner.lang = null;
      });
      assert_equals(getComputedStyle(subject.inner).backgroundColor, GREEN);
      subject.inner.dir = "rtl";
      assert_equals(getComputedStyle(subject.inner).backgroundColor, BLUE);
      subject.inner.dir = "ltr";
      assert_equals(getComputedStyle(subject.inner).backgroundColor, GREEN);
    }, "::part():dir() invalidation");

    test((t) => {
      t.add_cleanup(() => {
        subject.removeAttribute("dir");
      });
      assert_equals(getComputedStyle(subject.inner).backgroundColor, GREEN);
      subject.inner.setAttribute("dir", "rtl");
      assert_equals(getComputedStyle(subject.inner).backgroundColor, BLUE);
      subject.inner.removeAttribute("dir");
      assert_equals(getComputedStyle(subject.inner).backgroundColor, GREEN);
    }, "::part():dir() invalidation from setAttribute");
  </script>
</body>
